Metal filters

The high-pressure water supply service is employed for the operation of the ordinary filter pump, which finds so many applications in the laboratory. A typical all metal filter pump is illustrated in Fig. 11, 21, 1. It is an advantage to have a non-return valve fitted in the side arm to prevent sucking back if the water is turned off or if the water pressure is suddenly reduced. Theoretically, an efficient filter pump should reduce the pressure in a system to a value equal to the vapour pressure of the water at the temperature of the water of the supply mains. In practice this pressure is rarely attained (it is usually 4 10 mm. higher) because of the leakage of air into the apparatus and the higher temperature of the laboratory. The vapour pressures of water at 5°, 10°, 15°, 20° and 25° are respectively 6-5, 9-2,12-8, 17 5 and 23 8 mm. respectively. It is evident that the vacuum obtained with a water pump will vary considerably with the temperature of the water and therefore with the season of the year in any case a really good vacuum cannot be produced by a filter pump. 

Filters, acoustooptic Filters, holographic Filters, metallic Filter types Filtration... 

Several types of aggregate-bed filters are available which provide in-depth filtration. Both gravel and particle-bed filters have been developed for removal of dry particulates but have not been used extensively. Filters have also been developed using a porous ceramic or porous metal filter surface. 

One of the problems with early hydride systems was decrepitation of the alloy. Each time the metal hydride storage tank was recharged the particles would break down and eventually the particles became so small that they began to pass through the 5-p.m sintered metal filter which kept the hydride inside the tank. Addition of 0.5% manganese, which caused the decrepitation process to cease once the particles reached a size of about 10 p.m, solved this problem. 

The increasing use of sihconized coatings for weather durabiUty caused severe masking problems for the all-metal, filter mesh-like catalyst elements available in the 1970s. Interest in catalytic afterburners increased when dispersed-phase precious metal—alumin a-on-ceramic honeycomb catalysts offered economically attractive results. 

FIG. 18-111 Circiilar-plate fabricated-metal filter press. Star Systems Filtration Division.)... 

Figure 4-77B. Porous sintered metal filter elements. By permission, Pall Process Filtration Co.

Filtering. This is the final step after purification. Polymers, such as Teflon, are used widely in filters but, because of problems with their outgassing, are being increasingly replaced by ceramic and metal filters. 

A schematic diagram of the experimental apparatus is shown in Fig. 1. A rotating fluidized bed composes of a plenum chamber and a porous cylindrical air distributor (ID400xD100mm) made of stainless sintered mesh with 20(xm openings [2-3]. The horizontal cylinder (air distributor) rotates around its axis of symmetry inside the plenum chamber. There is a stationary cylindrical filter (ID140xD100mm, 20(o.m openings) inside the air distributor to retain elutriated fine particle. A binary spray nozzle moimted on the metal filter sprays binder mist into the particle bed. A pulse air-jet nozzle is also placed inside the filter, which cleans up the filter surface in order to prevent clogging. 

A method for correcting intensities from film data was proposed by Guinier [6] where two films were used. These were separated by a metal filter designed to absorb radiation X and let the more penetrating X/2 radiation through. Subtraction of the intensities on the second film from those on the first gave intensities free from X/2 contamination. 

Figure 8.5. Schematic view of continuous flow reaction setup for IL/scCC>2 systems (adapted from reference [81]). C compressor, CT cold trap, D dosimeter, DP depressuriser, F flowmeter, M mixer, MF metal filter, P HPLC pump, PT pressure transducer and thermocouple, R reactor, S styrene...

After the activation period, the reactor temperature was decreased to 453 K, synthesis gas (H2 CO = 2 1) was introduced to the reactor, and the pressure was increased to 2.03 MPa (20.7 atm). The reactor temperature was increased to 493 K at a rate of 1 K/min, and the space velocity was maintained at 5 SL/h/gcat. The reaction products were continuously removed from the vapor space of the reactor and passed through two traps, a warm trap maintained at 373 K and a cold trap held at 273 K. The uncondensed vapor stream was reduced to atmospheric pressure through a letdown valve. The gas flow was measured using a wet test meter and analyzed by an online GC. The accumulated reactor liquid products were removed every 24 h by passing through a 2 pm sintered metal filter located below the liquid level in the CSTR. The conversions of CO and H2 were obtained by gas chromatography (GC) analysis (micro-GC equipped with thermal conductivity detectors) of the reactor exit gas mixture. The reaction products were collected in three traps maintained at different temperatures a hot trap (200°C), a warm trap (100°C), and a cold trap (0°C). The products were separated into different fractions (rewax, wax, oil, and aqueous) for quantification. However, the oil and wax fractions were mixed prior to GC analysis. 

To measure the internal flow velocity in the duct, dust sampling was taken at various points along the vertical diameter. A pitot static tube and magnehelic gauge, shown in Figure 1, was the equipment used for these measurements. The duct humidity, tempertaure, and static pressure were measured to calculate the gas density. In determining the humidity, the wet and dry bulb temperature of a continuous sample stream was used. To prevent dust buildup on the wet bulb thermometer, an inline metal filter was inserted into the line. 

The mobile phase reservoir is made of an inert material, usually glass. There is usually a cap on the reservoir that is vented to allow air to enter as the fluid level drops. The purpose of the cap is to prevent particulate matter from falling into the reservoir. It is very important to prevent particulates from entering the flow stream. The tip of the tube immersed in the reservoir is fitted with a coarse metal filter. It functions as a filter in the event that particulates do find their way into the reservoir. It also serves as a sinker to keep the tip well under the surface of the liquid. In addition, in specially designed mobile phase reservoirs, this sinker/filter is placed into a well on the bottom of the reservoir so that it is completely immersed in solvent, even when the reservoir is running low. This avoids drawing air into the line under those conditions. These details are shown in Figure 13.3. 

Dust Separation It is usually necessary to recover the solids carried by the gas leaving the disengaging space or freeboard of the fluidized bed. Generally, cyclones are used to remove the major portion of these solids (see Gas-Solids Separation ). However, in a few cases, usually on small-scale units, filters are employed without the use of cyclones to reduce the loading of solids in the gas. For high-temperature usage, either porous ceramic or sintered metal filters have been employed. Multiple units must be provided so that one unit can be blown back with clean gas while one or more are filtering. 

Figure 7 (a) Sartorius absorption model (b) Sartorius dissolution model, a, Plastic syringe b, timer c, safety lock d, cable connector e, silicon tubes f, silicon-O-rings g, metal filter h, polyacryl reaction vessel. 

Assume that you have solid PbCh, a strip of zinc metal, filter paper, an electronic balance, and any other standard laboratory equipment. 

Stability Use hydralazine injection as quickly as possible after drawing through a needle into a syringe. Hydralazine changes color after contact with a metal filter. 

Add a metallic filter to a unit using an ESP when the ESP is at capacity... 

Another option to improve TSS performance is use of a sintered metal filter. This technology has typically been applied only as a fourth stage application on the TSS underflow. Pall has commercialized this barrier filter on the entire FCC flue gas on one commercial unit. 

Preparation of Mohr s Salt. Perjorm the experiment in a jume cupboard ) Put one gramme of a finely cut iron wire into a flask and dissolve it with heating in the calculated amount of 2 A sulphuric acid. Insert a funnel into the neck of the flask (for what purpose ). Keep the volume of the solution constant. After dissolving the metal, filter the solution and evaporate it until a crystalline film begins to form on its surface. What substance is in the solution ... 

Peykon s filter is another form of metallic filter... 

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